This invention relates to dual-piston reciprocating pump assemblies. It is particularly adapted, among many other possible applications, for use in liquid chromatography systems. In such systems, reciprocating pumps are used to pump chromatographic solvents (mobile phase) through a liquid chromatography column. A sample, which is injected into the top of the column, will separate as it is carried through the column. After separation occurs, a detector, recorder and other components are used for quantative or qualitative sample analysis.
Heretofore, difficulties were encountered during cylinder head assembly and disassembly due to frequent breakage of the sapphire piston. Further, prior art reciprocating pumps tended to have excessive pressure pulsations and uneven flow characteristics during operation. Moreover, such prior art pumps frequently were of a relatively complicated design, employing many moving parts, which were subject to wear.